Sustainable and efficient strategies for recovering spent LiFePO4-based lithium-ion batteries

Lithium iron phosphate (LiFePO 4 )-based lithium-ion batteries (LIBs), the mainstream LIBs, have a certain lifespan due to capacity loss and abnormal damage. Spent LiFePO 4 -based LIBs will eventually pose a significant threat to resources, the environment, and humans. Recovering spent LiFePO 4 -based LIBs becomes a hotspot field with the increasing environmental, economic, and social benefits. However, the conventional technologies have not yet been widely and maturely industrialized. Sustainable, efficient, low-cost methods and relevant mechanisms are still within investigation. In this review, the failure mechanisms of LiFePO 4 -based LIBs including the defect mechanism of LiFePO 4 were clarified. After conventional pretreatments according to industrial scale, black powders were obtained, and a series of methods were comprehensively described to treat black powders. The pyrometallurgy is potential as an auxiliary means to activate spent materials for subsequent hydrometallurgy. The direct regeneration is promising to obtain high value-added cathode materials if impurities are removed before. The hydrometallurgy is adept at addressing the separation and recycling metals. Hydrometallurgical processes are sustainable, efficient, and cost-effective to meet industrial demands for recovering spent LiFePO 4 -based LIBs. • The recovery processes of spent LiFePO 4 -type lithium-ion batteries are summarized. • The structure and failure mechanisms of LiFePO 4 in spent batteries are described. • Hydrometallurgical processes are emphasized based on real industrial needs. • The challenges and perspectives for recovering spent batteries are presented.